The present invention relates generally to the manufacture of articles from an elongated continuous strip, and more particularly concerns an improved method for producing closure tapes for brassieres.
Prior to the present invention considerable time and effort had to be expended to produce the individual tapes that are joined to the rear portion of a brassiere. In this type of wearing apparel, or undergarment, one tape having hooks thereon and another tape having eyes thereon are attached to opposite sides of the brassiere for adjustable coupling in a manner well known. In order to manufacture these tapes previously, they were cut from a layered continuous strip, and then sewn with hand control in order to join together separately the layers of material for the overlapping end tabs of the tape.
Applicants have now discovered that it is possible to utilize ultrasonic vibratory energy to form these tapes. The flexible layers of material from which the tapes are formed are generally woven with sufficient synthetic composition, generally at least thirty percent, to be capable of welding with ultrasonic energy.
Conventional ultrasonic welding techniques in which the strip of tape material was interposed between an ultrasonic horn and anvil would weld together the individual layers, but also the overlapping pair of tabs. This would be unacceptable in that the tabs are subsequently utilized to straddle a portion of the garment to which they are joined.
While the instant invention will be primarily described in conjunction with the manufacture of brassiere tapes, it will be apparent that the same principles disclosed herein may be applied to the manufacture of other articles formed from a continuous strip having layers of fabric, or material, and in which a pair of overlapping tabs or other protrusions are to extend therefrom.